Leadframe package with side solder ball contact and method of manufacturing

ABSTRACT

The present disclosure is directed to a leadframe package having a side solder ball contact and methods of manufacturing the same. A plurality of solder balls are coupled to recesses in a leadframe before encapsulation and singulation. After singulation, a portion of each solder ball is exposed on sidewalls of the package. This ensures that the sidewalls of the leads are solder wettable, which allows for the formation of stronger joints when the package is coupled to a substrate. This increased adhesion reduces resistance at the joints and also mitigates the effects of expansion of the components in the package such that delamination is less likely to occur. As a result, packages with a side solder ball contact have increased life cycle expectancies.

BACKGROUND Technical Field

The present disclosure is directed to a leadframe package having a sidesolder ball contact in order to improve solder wettability of the leadsidewall without additional post manufacturing plating.

Description of the Related Art

A typical leadframe package includes a die having its backside coupledto a leadframe and its active side coupled to various electricalcontacts. An encapsulant is then used to cover the combined die andleadframe to create the leadframe package. The resulting combination canbe connected to a circuit board, such as a printed circuit board (PCB),with solder using surface mount technology (SMT).

Although SMT allows for smaller packages, it also creates somedisadvantages. In particular, the solder joints between the package andthe PCB can be weakened due to the PCB and the package having differentcoefficients of thermal expansions (CTE). Thus, the reliability of thepackage may, in some cases, depend on the integrity of the solderjoints. But, most surface mount leadframe packages only have solder onthe bottom of the package and do not have solder wettable material toform connections between the package and the circuit board. In suchcases, the solder joints are weakened or cannot be formed because thereis no adhesion between the solder and the sidewall of the package. Thisresults in less contact area, a weaker bond and increased resistancewith the net outcome being a less reliable package. As packages reducein size, the available space for solder joints is further limited. Thus,strong solder bonds between the package and the PCB are desired.

Past responses to this issue have been to add a plating layer on theside of the leadframe package after manufacturing to provide forsidewall solder contact. However, plating after manufacturing requiresexpensive equipment and results in a less efficient manufacturingprocess. Further, these post plating techniques do not guaranteeadequate coverage of the lead sidewall and also do not allow theresulting package-substrate combination to be inspected by automatedsolder inspection. Without the assistance of automated solderinspection, the solder joints cannot be properly inspected, whichincreases the likelihood that products will leave the manufacturingfacility with problems that will manifest in a lower cycle life for theproduct.

BRIEF SUMMARY

Embodiments of the present disclosure are directed to leadframe packageswith a side solder ball contact and methods of manufacturing the same.In one embodiment, the package has a solder ball exposed on a sidewallof the package that extends from the leadframe and into the encapsulant.When the package is attached to a substrate, solder flows between theleadframe and the substrate and forms a connection with the solder ballto create an integral solder joint that covers a sidewall of each lead.This enables strong solder joints between the leads of the package andthe substrate. This also increases the solder contact area between thepackage and the substrate, which results in less resistance and a lowerthermal load per solder pin. This reduced thermal load allows for areduction in the number of pins required to handle the power supplyload. If fewer pins are required to carry the positive and negativepower supplies, then the chip can be made with fewer pins, saving money.It also allows for an increase in the number of signal and data pins inthe resulting device, if needed.

Other embodiments are directed to methods of manufacturing a leadframepackage with these characteristics. In an embodiment, a copper leadframeis plated on both sides before portions of the plate are removed and aplurality of recesses are formed on one side of the copper leadframe.Then, solder balls are attached to selected ones of these recesses, thedie is coupled to the leadframe and wires are coupled between the dieand the leadframe. An encapsulant is placed to cover the die, the wires,and the leadframe. After placing the encapsulant, the package isseparated by cutting through the solder balls to produce a package witha portion of a solder ball exposed on the sidewall of the package. Inother alternative embodiments of the process, the cutting process maycause a portion of the solder ball to spread onto a sidewall of theleadframe. Yet another embodiment of the process involves flowing thesolder ball during the original placement in order to form a bondbetween the metal plating layer on the leadframe and the solder ballbefore continuing manufacturing. An additional alternative embodimentincludes plating the leadframe after forming the plurality of recessesso that the solder balls can form a stronger connection with the metallayer. A final alternative embodiment describes plating a sidewall ofthe leadframe after singulation.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the drawings, identical reference numbers identify similar elementsor acts unless the context indicates otherwise. The sizes and relativepositions of elements in the drawings are not necessarily drawn toscale.

FIG. 1 is a cross-sectional view of an exemplary embodiment of aleadframe package having a side solder ball contact;

FIGS. 2A-2I are cross-sectional views of various stages of an assemblyprocess of leadframe packages, such as the package of FIG. 1, inaccordance with an embodiment of the present disclosure;

FIG. 3 is an alternative embodiment of a leadframe package with aportion of the side solder ball contact smeared onto a sidewall of theleadframe;

FIGS. 4A and 4B are cross-sectional views of an alternative embodimentof various stages of a leadframe package assembly process where thesolder ball is flowed over a portion of a metal plating layer on theleadframe during assembly;

FIGS. 5A-5D are cross-sectional views of an alternative embodiment ofvarious stages of a leadframe package assembly process where a pluralityof recesses are plated with a metal plating layer before a solder ballis attached to select recesses; and

FIG. 6 is an alternative exemplary embodiment of a leadframe packagehaving a metal plating layer on a sidewall of each of a plurality ofleads in the package.

DETAILED DESCRIPTION

In the following description, certain specific details are set forth inorder to provide a thorough understanding of various embodiments of thedisclosure. However, one skilled in the art will understand that thedisclosure may be practiced without these specific details. In otherinstances, well-known structures associated with electronic componentsand fabrication techniques have not been described in detail to avoidunnecessarily obscuring the descriptions of the embodiments of thepresent disclosure. Unless the context requires otherwise, throughoutthe specification and claims that follow, the word “comprise” andvariations thereof, such as “comprises” and “comprising,” are to beconstrued in an open, inclusive sense, that is, as “including, but notlimited to.”

The use of ordinals such as first, second and third does not necessarilyimply a ranked sense of order, but rather may only distinguish betweenmultiple instances of an act or structure.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure or characteristicdescribed in connection with the embodiment is included in at least oneembodiment. Thus, the appearances of the phrases “in one embodiment” or“in an embodiment” in various places throughout this specification arenot necessarily all referring to the same embodiment. Furthermore, theparticular features, structures, or characteristics may be combined inany suitable manner in one or more embodiments.

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include plural referents unless the contentclearly dictates otherwise. It should also be noted that the term “or”is generally employed in its sense including “and/or” unless the contentclearly dictates otherwise.

The present disclosure is generally directed to providing a package witha side solder ball contact. An exemplary embodiment of a package 20 witha side solder ball contact is shown in FIG. 1. In this embodiment, a die22 is coupled to a metal plating layer 23 positioned on a first surfaceof a die pad 24. The die pad has a first surface 64 and a second surface66, which are covered with the metal plating layer 23. A plurality ofleads 26 are spaced apart from the die pad 24. Each of the plurality ofleads 26 has a first side 28, a second side 30 and a sidewall 62. Eachsidewall 62 has a concave region 32 on an outermost surface of each ofthe plurality of leads 26. The first side 28 and the second side 30 arecovered by the metal plating layer 23. In other embodiments, as will bedescribed below, the metal plating layer 23 is also positioned on theconcave region 32 and on the sidewall 62 of each of the plurality ofleads 26. A plurality of wires 34 coupled between the die 22 and theleads 26 provide an electrical connection between the die 22 and theleads 26. The concave region 32 on each of the leads 26 has a size and ashape for receiving one of the plurality of solder balls 36. The die 22,the wires 34 and the solder balls 36 are covered by an encapsulant 38 toform a leadframe package 20. In this embodiment, the leadframe package20 is coupled to a substrate 21 with solder 25, although the package 20can be manufactured and sold separately.

In the leadframe package 20, the solder balls 36 extend outward fromeach of the plurality of leads and into the encapsulant 38. In addition,the package 20 has a sidewall 27 with a first portion of the solderballs 36 covered by the encapsulant 38 and a second portion of thesolder balls 36 exposed to an exterior environment on a first side andabutting both the encapsulant 38 and the concave region 32 of each ofthe plurality of leads 26 on a second side. This allows the plurality ofsolder balls 36 to act as a preliminary solder material to ensuremaximum solder coverage of the sidewall 62 of each of the plurality ofleads 26 when the package 20 is mounted to the substrate 21. Uponcombining the package 20 with the substrate 21, the solder used for thecoupling flows and combines with the plurality of solder balls 36 toform a plurality of integral solder portions 54 that cover the entiresidewall 62 of each of the plurality of leads 26. This coverage ensuresa stronger solder joint, which helps resists the effects of differingCTE between elements in the system, thus increasing the expected cyclelife of the finished package 20 over known packages. In addition, thepresence of solder on the exterior of the package 20 allows the package20 to be inspected with automated solder inspection, which enables themanufacturer to detect defects in the soldering process that couldultimately lead to lower cycle life.

An exemplary embodiment of a method of manufacturing the package 20 isshown in FIG. 2A. In this embodiment, a leadframe 29 is plated on afirst side 31 and a second side 33 with the metal plating layer 23. Theleadframe 29 is typically comprised of copper or a copper alloy due itsconductivity and cost advantages, although other metals may be used. Themetal plating layer 23 typically consists of at least one of nickel,palladium or gold, although each of these alternatives may be usedexclusive of the others in addition to other alternatives. The mainreason for plating the leadframe 24 is that most solders typically forma weak mechanical bond with the copper of the leadframe. In other words,most solders used for packages form a weak mechanical bond with copper.However, nickel, palladium and gold have strong mechanical compatibilitywith both the solder and the copper. Therefore, the plating layer 23acts as an intermediary between the copper and the solder in order toincrease adhesion and provide for a strong bond between the solder, theplating layer 23 and the copper while maintaining desirable electricalproperties. However, using different solder or leadframe materials mayreduce or eliminate the need for plating.

Once the plating is complete, portions 44 of the plating layer 23 areremoved on both surfaces of the leadframe 29 as shown in FIG. 2B. Theseportions 44 can be removed with either a masking process followed by wetor dry etch, a laser, or a mechanical blade. There are many known waysto pattern a plating layer on a leadframe. In the spaces left byremoving the portions 44, a first plurality of recesses 46 and a secondplurality of recesses 48 are formed in a body of the leadframe 29 on thefirst surface 31, as in FIG. 2C. In this embodiment, forming the firstplurality of recesses 46 and the second plurality of recesses 48 is doneby wet etching the leadframe 29 with an etch that is selective to removecopper and not the plating layer, although other cutting, etching orforming techniques may be used in other embodiments. The first pluralityof recesses 46 have a size and a shape configured to receive a solderball.

Once the recesses are formed, the plurality of solder balls 36 arecoupled to each of the first plurality of recesses 44 as in FIG. 2D. Inthis embodiment, the solder balls 36 form an intermetallic connectionwith a peripheral edge 35 of each of the first plurality of recesses 44and are placed before encapsulation and singulation. Once the solderballs 36 are in place, a die 22 is coupled to the metal layer 23 on thefirst surface 31 of the leadframe 29, as in FIG. 2E. The plurality ofwires 34 create an electrical connection between the die 22 and theleadframe 29 and an adhesive layer 19 connects the backside of the dieto the top of the leadframe 29. With these elements in place, theencapsulant 38 is added over the die 22, the plurality of solder balls36, the plurality of wires 34 and the leadframe 29. The encapsulant 38also fills the second plurality of recesses 48.

The encapsulant 38 is applied to the system at a selected hightemperature and appropriate pressure. For example, some moldingcompounds will flow and form around the various components between 160and 180 degrees Celsius. Some solders and solder balls have a meltingpoint below this temperature. However, recent developments have createdsolders with a melting point at or above 200 degrees Celsius andtherefore the plurality of solder balls 36 will not melt and flow whenthe encapsulant 38 is applied if a high temperature solder is used. Theencapsulant 38 can be an acceptable molding compound, polymer, epoxy orother acceptable encapsulant having the properties described hereinrelative to the solder. With the solder balls 36 present when theencapsulant 38 is applied, there is balancing and tradeoff in theselection of the two components, solder and encapsulant, to selectmaterials that are compatible with each other in the same process.

In particular, an encapsulant 38 is selected that has an applicationtemperature which is lower than the melting temperature of the fullyformed solder balls 36 for the type of solder used. This can beaccomplished by having either a high temperature melting point of thesolder balls 36 or a low temperature melting point of the encapsulant 38that creates encapsulant 38. Thus, one option is to use a lowtemperature encapsulant 38 that will flow at a temperature lower thanthe melting temperature of standard solder balls 36. In addition, sincethe encapsulant 38 flows differently with different pressures andtemperatures, and may be used in a transfer mold, a compression mold, orother type of mold, the encapsulant 38 can be selected with theproperties of the solder ball 36 already known to ensure that, based onthe type of molding process used, the solder balls 36 remain in the samelocation and remain relatively stable when subjected to the varioustemperatures and pressures involved in the encapsulation process. It isacceptable if the solder is brought toward the melting temperature and,perhaps, partially reflows; however, the temperature and pressure forthe encapsulation process should be selected to ensure that the solderballs 36 remain substantially in the same place and shape become evenmore tightly bonded o the leadframe 29.

One benefit of forming the encapsulant 38 after the solder ball ispresent is that the additional temperature and pressure heating whichthe solder ball 36 undergoes will tend to more solidly attach the solderball 36 to the leadframe 29, as well as to the plating layer 23, whileat the same time solidly embedding the solder ball 36 into theencapsulant 38. In most selections of the materials for the encapsulant38 and the solder balls 36, a combination will be selected that willcause the solder balls 36 to mechanically bond with, and be rigidlyattached to, the encapsulant 38.

After encapsulating, remaining portions 50 of the leadframe 29 oppositethe plurality of solder balls 36 and the second plurality of recesses 48are removed as shown in FIG. 2G. Removing these portions 50 isolates thedie pad 24 from the plurality of leads 26 so that an improper electricalconnection does not short the leads to each other. The removal of thebackside of leadframe 29 can be carried out by any acceptable technique,such as etching with a chemical etch that is selective to etch theleadframe material and not the plating layer 23, by laser cutting, amechanical blade or other acceptable technique.

As shown in FIG. 2H, a mechanical blade or other dicing technique isused to separate the resulting package 20 at the locations 52. As shown,the locations 52 correspond to approximately a midpoint of the pluralityof solder balls 36, although it is possible to make the cut such that adifferent proportion of the plurality of solder balls 36 remains. Inaddition, removing the portions 50 and separating the package 20 fromthe remaining material at locations 52 after the solder balls 36 arecoupled to the leadframe 29 ensures that the solder balls 36 occupy theconcave region 32 of each of the plurality of leads 26. In thisembodiment, the concave regions 32 are a top side recess filled with asolder ball 36. The solder ball 36 has a portion remaining that allowsthe solder to flow down and cover the entire sidewall 62 of each of theplurality of leads 26 during reflow when the package 20 is attached tothe substrate 21. This helps to ensure complete solder coverage of thesidewall 62 and results in a stronger solder joint.

Next, as shown in FIG. 2I, the package 20 is coupled to the substrate 21with solder 25. When the solder 25 flows between the plurality of leads26 and the substrate 21, the solder 25 joins with the plurality ofsolder balls 36 to form the plurality of integral solder portions 54.The integral solder portions 54 extend beyond the sidewall 62 and theconcave region 32 of each of the plurality of leads 26, which createsadditional strength against the effects of different CTEs between thematerials in the package 20 compared to packages without solder wettablesides.

If the package is attached to a substrate where the solder must beheated to about 200 degrees Celsius, then there might be a concern thatthe encapsulant 38, which is of a thermoset type in this embodiment,would degrade or decompose. However, once the encapsulant 38 is cured byheat and pressure during the encapsulation process, then the thermosetencapsulant 38, does not degrade and cannot be reshaped by melting andreprocessing at standard solder melting temperatures. Instead, if theencapsulant 38 is a thermoset type, it does not experience anysignificant degrading at temperatures below 400 degrees Celsius. Thus,only if the temperature is raised above 400 degrees Celsius after curingdoes degradation or decomposition of the encapsulant 38 become an issueof concern, which is well above any solder application or reflowtemperatures.

In alternative embodiments, it is possible to use an encapsulantcomprised of thermoplastic, which can be reshaped by melting andreprocessing after curing. In this case, the concern is that theencapsulant would liquefy during the solder application and reflowprocess. However, a thermoplastic material may be selected, based on itsproperties, to be compatible with the solder as mentioned above. Inother words, curing the thermoplastic encapsulant can raise the meltingpoint of the encapsulant to above 300 degrees Celsius, which is abovethat of the melting point of the solder to be used.

Thus, soldering the package to the substrate will not raise thetemperature of the encapsulant to a point where it will begin to melt.Having the solder balls partially embedded in the encapsulant cantherefore be safely used with both a thermoset and a thermoplasticencapsulant.

The solder balls 36 and the encapsulant 38, whether of a thermoset or athermoplastic type, can be used in combination in a final package,while, of course, there will be time and temperature monitoring in thefinal soldering of the package to the substrate 21. Namely, theencapsulant 38, after it is cured, whether by UV curing, additional heatafter the first mold flow, a hardener which becomes more rigid over timeas it cures, or other curing technique, will remain rigid at extremelyhigh temperatures. For example, an encapsulant 38 of a thermoset type isselected which, during the encapsulation process may flow at atemperature range between 140 to 180 degrees Celsius and then, afterfull curing, will remain solid and and will not degrade or decomposeeven though the temperature may exceed 400 degrees Celsius. Suchencapsulant 38, which prior to being cured has good flow propertiesbelow 180 degrees Celsius, can after curing remain a solid attemperatures above 400 degrees Celsius, are well known in the art andcommercial available from a number of suppliers. One of ordinary skillin the art can use such an encapsulant 38 having these properties with asolder having complementary properties as disclosed herein.

In an alternative embodiment shown in FIG. 3, separating the packagewith a mechanical blade or other dicing techniques creates enough forceto smear or otherwise spread the solder ball 36. This smearing orspreading of the solder ball 36 can be accomplished by a number oftechniques. For example, the mechanical motion of a moving blade maycause pressure against the exposed portion of the solder ball 36, asshown in FIG. 2H, that is above the concave portion and may press itsomewhat into the concave region 62. Thus, the mechanical pressure of ablade contacting the solder ball 36 will press some of the solder ballmaterial, some from the upper portion of the solder ball, to bedepressed into and fill some of the concave region 62 in the leadframe29. This causes a portion 56 of the first solder ball to press down intothis region and create a stronger contact to the lead 26. Alternatively,the singulation of the package, whether by cutting with a blade or lasercutting, may raise the temperature of the solder balls 36 at the cutinterface to a point slightly melting the solder material that comprisesthe plurality of solder balls 36 so that a spreading or smearing occurs.In this case, the heat causes a portion 56 of a first solder ball toflow down, or “smear,” onto a lead portion 58 of a first sidewall 68 ofthe package 43. Similarly, a portion 56 of a second solder ball issmeared onto the lead portion 58 of a second sidewall 70 of the package43. This result is advantageous because it decreases the separationdistance between the plurality of solder balls 36 of the package 43 anda substrate. As such, solder that is added when coupling the package 43to the substrate will not have to flow as far in order to form aconnection with the plurality of solder balls 36. This decrease in flowdistance helps to ensure that any solder added when connecting thepackage 43 to the substrate will form a complete connection, or in otherwords, will flow completely to the plurality of solder balls 36 in orderto form the plurality of integrated solder pieces described above.

FIG. 4A shows an alternative embodiment of a process for forming aleadframe package 45 with a side solder ball contact. In some cases, astronger connection is desired between the plurality of solder balls 36and the leadframe 29. In these circumstances, the plurality of solderballs 36 can be reflowed after deposition beyond the peripheral edge 35so that the solder balls 36 form an intermetallic connection with themetal plating layer 23 on the first surface 31 of the leadframe 29. Alarger amount of solder for the balls 36 can be added and then a solderreflow heat treatment step performed to cause the solder ball 36 tospread out into the layer 31, as shown in FIG. 4A. Then, the processcontinues as described above with respect to FIGS. 2A-I. The endproduct, shown in FIG. 4B, has a plurality of integral solder portions60 where a portion of the solder ball 36 extends beyond the peripheraledge 35 and contacts the metal plating layer 23 on each of the pluralityof leads 26. Increasing the contact area between the plurality ofintegral solder portions 60 and the metal layer 23 further increases thestrength of the solder joints formed between the leadframe package 45and the substrate 21. In addition, forming the bond between the metallayer 23 and the plurality of solder balls 36 when the solder balls 36are placed ensures that the solder balls 36 remain in their properlocation during the various processing steps.

An alternative embodiment of a process for manufacturing a leadframepackage with a side solder ball contact is shown in FIG. 5A. In thisembodiment, the first plurality of recesses 46 and the second pluralityof recesses 48 are formed in the body of the leadframe 29 from the firstsurface 31 before the plating layer 23 is added. Once the recesses areformed, the metal plating layer 23 is formed on the leadframe 29 as inFIG. 5B. Notably, the metal plating layer 23 covers the first pluralityof recesses 46 and the second plurality of recesses 48. This allows theplurality of solder balls 36 to form a strong intermetallic connectionwith the metal plating layer 23 when the solder balls 36 are coupled tothe leadframe 29, as in FIG. 5C. This increased bond reduces thelikelihood that the different CTE between the various metals in thefinal package will result in separation, or delamination, of the solderballs 36 from the leadframe 29. In addition, this provides additionalmechanical strength to assist the solder balls 36 to remain in theirintended positions during the rest of the processing steps.

After coupling the solder balls 36 to the metal layer 23, the processcontinues as in other embodiments until a leadframe package 37 isformed, as in FIG. 5D. The package 37 has a portion of each solder ball36 exposed on a first sidewall 74 and a second sidewall 72 of thepackage 37. The leadframe package 37 differs from other embodimentsbecause the metal layer 23 covers the concave region 32 of each of theplurality of leads 26. As such, a strong bond forms between theplurality of solder balls 36 and the concave region 32, which furtherincreases the integrity of the solder joints that are formed between theplurality of leads 26 and the substrate 21. However, this embodimentdoes not include having the metal layer 23 positioned on a sidewall 62of each of the plurality of leads. In order to achieve such anarrangement, a different process may be utilized.

An alternative embodiment of a leadframe package 39 is shown in FIG. 6.In this embodiment, the metal layer 23 is formed on the sidewall 62 ofeach of the plurality of leads 26. As such, the sidewall 62 and theconcave region 32 of each of the plurality of leads 26 can form a strongbond with the solder 25 and the plurality of solder balls 36. To createa package 39 with these characteristics, the manufacturing processbegins similar to the process described with respect to FIGS. 5A-C.However, once the leadframe 29 is etched from the bottom sidesingulation, as in FIG. 2G, the remaining portion of the sidewall isplated with the metal layer 23. Namely, after step 2G is performed, theunderside of the leadframe 29 has a plating layer 23 applied across theentire underside. This may serve to somewhat thicken the lower layerwhile at the same time placing a plating layer 23 on the concaveportions of the leadframe 29 and the die pad 24. This additional platinglayer 23 can be formed by electroplating, simple blanket deposition, orother technique on the backside of the leadframe assembly 29 shown inFIG. 2G.

While this requires an additional manufacturing step, positioning themetal layer on the sidewall 62 of each of the leads 26 allows solder toflow onto the metal layer 23 covering the sidewall 62 when the leadframepackage 39 is attached to the substrate 21. This maximizes the contactarea between a plurality of integral solder portions 54 and each of theplurality of leads 26, which, in turn, maximizes the solder jointstrength between the plurality of leads 26 and the substrate 21.

As will be appreciated, only a single leadframe 29 is shown in FIGS.2A-2H; however, the leadframe 29 will typically be one in an arrayseveral hundred or, perhaps, several thousand leadframes that areconnected in a single contiguous strip in a manner well known in theart. The die are placed at the appropriate place on the leadframe arrayin which many hundreds or thousands of die are present with the plating,wire bonding, soldering, applying the encapsulant 38, and completing theencapsulation occurs on the large array with many thousands beingencapsulated at the same time. After this process, shown in FIG. 2H, theindividual packages are singulated to obtain the final package as shownin the respective figures, such as FIGS. 2I, 4B, 5 and 6.

The various embodiments described above can be combined to providefurther embodiments. All of the U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet areincorporated herein by reference, in their entirety. Aspects of theembodiments can be modified, if necessary to employ concepts of thevarious patents, applications and publications to provide yet furtherembodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

1. A device, comprising: a lead frame having a plurality of leads spacedapart from each other, each of the plurality of leads having a firstside, a second side and a sidewall, the sidewall having a concave regionon an outermost surface; a die electrically coupled to each theplurality of the leads; a plurality of solder balls, each of theplurality of solder balls coupled to a respective concave region of eachsidewall of each of the plurality of leads, each of the plurality ofsolder balls extending outward from each of the plurality of leads; andan encapsulant that encases the die and a first portion of each of theplurality of solder balls, a second portion of each of the plurality ofsolder balls having a first side exposed to an exterior environment anda second side abutting both the encapsulant and one of the plurality ofleads.
 2. The device of claim 1 further including: a metal plating layerpositioned on the first side and the second side of each of theplurality of leads.
 3. The device of claim 2 wherein the couplingbetween each of the plurality of solder balls and each of the pluralityof leads further comprises an intermetallic connection between each ofthe plurality of solder balls and a peripheral edge of the metal platinglayer positioned on the first side of each of the plurality of leads. 4.The device of claim 3 wherein the coupling further comprises anintermetallic connection between each of the plurality of solder ballsand the metal plating layer on the first side of one of the plurality ofleads.
 5. The device of claim 2 further comprising the metal platinglayer positioned on the concave region of each of the plurality ofleads.
 6. The device of claim 5 wherein the coupling between each of theplurality of solder balls and each of the plurality of leads furthercomprises an intermetallic connection between each of the plurality ofsolder balls and the metal plating layer on the concave region of eachof the plurality of leads.
 7. The device of claim 1 further including: asubstrate coupled to each of the plurality of leads with solder; and aplurality of integral solder portions, each of the plurality of integralsolder portions comprised of one of the plurality of solder balls andthe solder between the substrate and one of the plurality of leads.
 8. Amethod, comprising: removing portions of a metal layer on a firstsurface and a second surface of a leadframe; forming a plurality ofrecesses in the first surface of the leadframe; coupling a solder ballto each of the plurality of recesses; coupling a die to the metal layeron the first surface of the leadframe; encapsulating the die and atleast a portion of each solder ball with an encapsulant, a portion ofeach solder ball extending from a sidewall of the leadframe and into abody of the encapsulant; removing remaining portions of a body of theleadframe opposite the plurality of recesses; and cutting theencapsulant, the leadframe and the plurality of solder balls to form aleadframe package.
 9. The method of claim 8 wherein the cutting furtherincludes: exposing a first solder ball portion on a first sidewall ofthe leadframe package and exposing a second solder ball portion on asecond sidewall of the leadframe package.
 10. The method of claim 9wherein the cutting further includes: smearing a portion of a firstsolder ball onto a first lead portion of the first sidewall; andsmearing a portion of a second solder ball onto a second lead portion ofthe second sidewall.
 11. The method of claim 9 further including:coupling the leadframe package to a substrate with a solder, thecoupling including forming a plurality of integral solder portions, eachof the plurality of integral solder portions comprised of a piece ofsolder and one solder ball.
 12. The method of claim 8 wherein formingthe first surface of the leadframe includes forming by etching.
 13. Themethod of claim 8 wherein coupling the solder ball to each of theplurality of recesses further includes: flowing the solder ball over aportion of the metal layer on the first surface of the leadframe; andforming an intermetallic connection between the metal layer on the firstsurface of the leadframe and the plurality of solder balls.
 14. Themethod of claim 8 wherein cutting the encapsulant, the leadframe and theplurality of solder balls includes cutting with a mechanical blade. 15.A method, comprising: forming a plurality of recesses in a first surfaceof a leadframe; forming a metal layer on the first surface and on asecond surface of the leadframe, the forming including the metal layercovering the plurality of recesses; coupling a solder ball to the metallayer on each of the plurality of recesses; coupling a die to the metallayer on the first surface of the leadframe; encapsulating the die andat least a portion of each solder ball with an encapsulant, a portion ofeach solder ball extending from a sidewall of the leadframe and into abody of the encapsulant; removing remaining portions of the leadframeand the metal layer opposite the plurality of recesses; and cutting theencapsulant, the leadframe and the plurality of solder balls to form aleadframe package.
 16. The method of claim 15 wherein the cuttingfurther includes: exposing a first solder ball portion on a firstsidewall of the leadframe package and exposing a second solder ballportion on a second sidewall of the leadframe package.
 17. The method ofclaim 15 further including: coupling the leadframe package to asubstrate with a solder, the coupling including forming a plurality ofintegral solder portions, each of the plurality of integral solderportions comprised of a piece of solder and one solder ball.
 18. Themethod of claim 16 wherein the cutting further includes: smearing aportion of a first solder ball onto a first lead portion of the firstsidewall; and smearing a portion of a second solder ball onto a secondlead portion of the second sidewall.
 19. The method of claim 15 whereinforming the plurality of recesses includes forming by etching.
 20. Themethod of claim 16 further including: forming a metal layer on a firstlead portion of the first sidewall; and forming a metal layer on asecond lead portion of the second sidewall.